In a retail checkout station, there are particular types of actions that result in access to the cash register. These actions include, for example, transaction void, item void, item refund, and manager override. With a transaction void, the entire transaction is cancelled, either due to an error or because the customer decided not to purchase items at the point of sale. With an item void, a single item is voided from the transaction due to similar reasons.
Also, with an item refund, a customer returns to the store and a refund is issued for an item. Further, with a manager override, a manager overrides the normal register function resulting in special privileges, such as opening the cash drawer.
All of the above actions, however, can be exploited to commit fraud. As such, a fraudulent action can be determined based on visual analysis of the regions occupied by customers and cashiers. For example, for a transaction void, item void, and item refund, a customer should always be present. For a manager override, there should be two people present in the cashier area, and an override occurring when a single person is present is an indication that fraud might be occurring.
As such, certain types of (for example, checkout) transactions require certain employees and/or customers with specific authority, and detecting such transactions without visual detection of these authorized persons raises suspicion of the transaction. Also, as the number of lanes to monitor increases, examining all of these events becomes disadvantageously time-consuming.